Face seal

Abstract

A face seal between the rotor and stator of a fluid-operated rotory motor is formed by a seal member formed of a low friction material having a low surface coefficient of friction and a low memory and extruded into sealing engagement with an associated part by an elastomeric seal member as the rotor and stator are assembled.

What is claimed: 
     
       1. A method of providing a fluid tight seal between a shaft and a housing in which it is journaled, comprising the steps of providing a bushing on said shaft, said bushing having an outer annular surface disposed in spaced relation to an adjacent internal annular surface of said housing and having an annular groove facing said surface of said housing,   mounting in said groove an annular sealing member and an annular elastomeric member, said elastomeric member being disposed between a bottom of said groove and a bottom of said sealing member to exert an outward radial force on said sealing member when said elastomeric member is compressed, said sealing member extending outwardly from said groove,   forcing said shaft in an axial direction into said housing to press said sealing member against said internal annular surface of said housing to exert on said sealing member an inwardly directed radial force greater than the compression strength of said sealing member thereby to extrude said sealing member outwardly of said groove into the space provided between said outer annular surface of said bushing and said adjacent surface of said housing to provide a rotary seal between said sealing member and said housing.   
     
     
       2. A method according to claim 1 comprising the further step of providing the internal annular surface of said housing against which said sealing member is pressed with an outwardly divergent configuration.   
     
     
       3. In a fluid operated, reciprocatory rotary motor of the type having a body having a cylindrical bore therein, first and second head assemblies fixedly mounted to said body over the respective ends of said bore,   a shaft extending through said bore and through said head assemblies,   first and second annular thrust bearings respectively disposed in said first and second head assemblies,   said shaft being journaled in said bearings,   a radially disposed, longitudinal vane fixedly mounted to said shaft and extending from said first head assembly to said second head assembly,   first sealing means carried by said body for sealing said shaft to said body and to said assemblies,   second seal means carried by said vane for sealing said vane to said body and to said head assemblies,   means for selectively admitting fluid under pressure into said bore to one side or the other of said vane,   said first head assembly including a head member having a central bore and a counterbore through which said shaft extends,   an annular thrust bushing compressed between an annular shoulder on said shaft and said first thrust bearing,   said annular thrust bushing having an annular groove defining an outer wall surface,   an annular end plate compressed between an annular end surface of said body and an annular facial surface on said head member,   said annular end plate having a central bore defining an inner annular wall surface, said inner wall surface being disposed in spaced relation to the outer annular wall surface of said thrust bushing,   an annular seal member formed of a rigid material having a low coefficient of surface friction and a low memory,   an annular elastomeric member compressed between said seal member and said annular groove of said thrust bushing, and   said seal member being forced by said elastomeric member into sealing engagement with the inner annular surface of said end plate and being extruded into the space provided between said inner annular surface and the outer annular wall surface of said thrust bushing.   
     
     
       4. A reciprocating motor according to claim 3 wherein said space provided between said inner annular surface of said end plate and the outer annular wall surface of said thrust bushing is increasing in a direction away from said body. 
     
     
       5. A reciprocatory motor according to claim 4 wherein said inner annular surface of said end plate is frusto-conical.